Mechanical apparatus for cleaning carpets and other flooring have been in existence for sometime, and in general the carpet cleaners operate with similar principles by injecting a cleaning fluid carried by hot water or steam into the carpet, agitating the carpet and extracting at least the majority of the now soiled liquid.
Particular references known to the inventor include U.S. Pat. No. 3,624,668 granted to Krause, Nov. 30, 1971, which discloses a rug cleaning and rinsing device wherein a plurality of rotating pick-up nozzles and one rotating spray nozzle are mounted within a stationary shroud. The shroud forms a plenum around the rotating portion through which the vacuum is drawn. The liquid is fed downwardly through the center of the rotating element.
U.S. Pat. No. 4,264,999 granted to Monson, May 5, 1981 discloses a mechanism wherein both the liquid application and vacuum withdrawal are on a rotating member covered by a stationary shroud.
U.S. Pat. No. 4,441,229 granted to Monson, Apr. 10, 1984 discloses a device wherein the vacuum and fluid are fed through the center of the rotating cleaning head and the vacuum elements are mounted on flexible members which in turn support the entire cleaning device.
U.S. Pat. No. 4,692,959 granted to Monson, Sep. 15, 1987 discloses a carpet cleaning device wherein cleaning liquid and vacuum are both fed through the center of the rotating hub and the individual vacuum heads rotate about their axis while simultaneously rotating about the main hub axis.